1
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Schuster KH, Zalon AJ, DiFranco DM, Putka AF, Stec NR, Jarrah SI, Naeem A, Haque Z, Zhang H, Guan Y, McLoughlin HS. ASOs are an effective treatment for disease-associated oligodendrocyte signatures in premanifest and symptomatic SCA3 mice. Mol Ther 2024; 32:1359-1372. [PMID: 38429929 PMCID: PMC11081874 DOI: 10.1016/j.ymthe.2024.02.033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2023] [Revised: 12/18/2023] [Accepted: 02/27/2024] [Indexed: 03/03/2024] Open
Abstract
Spinocerebellar ataxia type 3 (SCA3) is the most common dominantly inherited ataxia. Currently, no preventive or disease-modifying treatments exist for this progressive neurodegenerative disorder, although efforts using gene silencing approaches are under clinical trial investigation. The disease is caused by a CAG repeat expansion in the mutant gene, ATXN3, producing an enlarged polyglutamine tract in the mutant protein. Similar to other paradigmatic neurodegenerative diseases, studies evaluating the pathogenic mechanism focus primarily on neuronal implications. Consequently, therapeutic interventions often overlook non-neuronal contributions to disease. Our lab recently reported that oligodendrocytes display some of the earliest and most progressive dysfunction in SCA3 mice. Evidence of disease-associated oligodendrocyte signatures has also been reported in other neurodegenerative diseases, including Alzheimer's disease, amyotrophic lateral sclerosis, Parkinson's disease, and Huntington's disease. Here, we assess the effects of anti-ATXN3 antisense oligonucleotide (ASO) treatment on oligodendrocyte dysfunction in premanifest and symptomatic SCA3 mice. We report a severe, but modifiable, deficit in oligodendrocyte maturation caused by the toxic gain-of-function of mutant ATXN3 early in SCA3 disease that is transcriptionally, biochemically, and functionally rescued with anti-ATXN3 ASO. Our results highlight the promising use of an ASO therapy across neurodegenerative diseases that requires glial targeting in addition to affected neuronal populations.
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Affiliation(s)
- Kristen H Schuster
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Annie J Zalon
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109, USA
| | | | - Alexandra F Putka
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109, USA; Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI 48109, USA
| | - Nicholas R Stec
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Sabrina I Jarrah
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Arsal Naeem
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Zaid Haque
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Hanrui Zhang
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI 48109, USA
| | - Yuanfang Guan
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI 48109, USA
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2
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Incebacak Eltemur RD, Nguyen HP, Weber JJ. Calpain-mediated proteolysis as driver and modulator of polyglutamine toxicity. Front Mol Neurosci 2022; 15:1020104. [PMID: 36385755 PMCID: PMC9648470 DOI: 10.3389/fnmol.2022.1020104] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 09/26/2022] [Indexed: 09/22/2023] Open
Abstract
Among posttranslational modifications, directed proteolytic processes have the strongest impact on protein integrity. They are executed by a variety of cellular machineries and lead to a wide range of molecular consequences. Compared to other forms of proteolytic enzymes, the class of calcium-activated calpains is considered as modulator proteases due to their limited proteolytic activity, which changes the structure and function of their target substrates. In the context of neurodegeneration and - in particular - polyglutamine disorders, proteolytic events have been linked to modulatory effects on the molecular pathogenesis by generating harmful breakdown products of disease proteins. These findings led to the formulation of the toxic fragment hypothesis, and calpains appeared to be one of the key players and auspicious therapeutic targets in Huntington disease and Machado Joseph disease. This review provides a current survey of the role of calpains in proteolytic processes found in polyglutamine disorders. Together with insights into general concepts behind toxic fragments and findings in polyglutamine disorders, this work aims to inspire researchers to broaden and deepen the knowledge in this field, which will help to evaluate calpain-mediated proteolysis as a unifying and therapeutically targetable posttranslational mechanism in neurodegeneration.
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Affiliation(s)
- Rana Dilara Incebacak Eltemur
- Department of Human Genetics, Ruhr University Bochum, Bochum, Germany
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Huu Phuc Nguyen
- Department of Human Genetics, Ruhr University Bochum, Bochum, Germany
| | - Jonasz Jeremiasz Weber
- Department of Human Genetics, Ruhr University Bochum, Bochum, Germany
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
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3
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Radmard S, Zesiewicz TA, Kuo SH. Evaluation of Cerebellar Ataxic Patients. Neurol Clin 2022; 41:21-44. [DOI: 10.1016/j.ncl.2022.05.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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4
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Loureiro JR, Castro AF, Figueiredo AS, Silveira I. Molecular Mechanisms in Pentanucleotide Repeat Diseases. Cells 2022; 11:cells11020205. [PMID: 35053321 PMCID: PMC8773600 DOI: 10.3390/cells11020205] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 01/04/2022] [Accepted: 01/05/2022] [Indexed: 02/01/2023] Open
Abstract
The number of neurodegenerative diseases resulting from repeat expansion has increased extraordinarily in recent years. In several of these pathologies, the repeat can be transcribed in RNA from both DNA strands producing, at least, one toxic RNA repeat that causes neurodegeneration by a complex mechanism. Recently, seven diseases have been found caused by a novel intronic pentanucleotide repeat in distinct genes encoding proteins highly expressed in the cerebellum. These disorders are clinically heterogeneous being characterized by impaired motor function, resulting from ataxia or epilepsy. The role that apparently normal proteins from these mutant genes play in these pathologies is not known. However, recent advances in previously known spinocerebellar ataxias originated by abnormal non-coding pentanucleotide repeats point to a gain of a toxic function by the pathogenic repeat-containing RNA that abnormally forms nuclear foci with RNA-binding proteins. In cells, RNA foci have been shown to be formed by phase separation. Moreover, the field of repeat expansions has lately achieved an extraordinary progress with the discovery that RNA repeats, polyglutamine, and polyalanine proteins are crucial for the formation of nuclear membraneless organelles by phase separation, which is perturbed when they are expanded. This review will cover the amazing advances on repeat diseases.
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Affiliation(s)
- Joana R. Loureiro
- Genetics of Cognitive Dysfunction Laboratory, i3S- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal; (J.R.L.); (A.F.C.); (A.S.F.)
- Institute for Molecular and Cell Biology, Universidade do Porto, 4200-135 Porto, Portugal
| | - Ana F. Castro
- Genetics of Cognitive Dysfunction Laboratory, i3S- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal; (J.R.L.); (A.F.C.); (A.S.F.)
- Institute for Molecular and Cell Biology, Universidade do Porto, 4200-135 Porto, Portugal
- Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, 4050-313 Porto, Portugal
| | - Ana S. Figueiredo
- Genetics of Cognitive Dysfunction Laboratory, i3S- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal; (J.R.L.); (A.F.C.); (A.S.F.)
- Institute for Molecular and Cell Biology, Universidade do Porto, 4200-135 Porto, Portugal
- Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, 4050-313 Porto, Portugal
| | - Isabel Silveira
- Genetics of Cognitive Dysfunction Laboratory, i3S- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal; (J.R.L.); (A.F.C.); (A.S.F.)
- Institute for Molecular and Cell Biology, Universidade do Porto, 4200-135 Porto, Portugal
- Correspondence: ; Tel.: +351-2240-8800
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5
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McIntosh CS, Watts GF, Wilton SD, Aung-Htut MT. Splice correction therapies for familial hypercholesterolemic patients with low-density lipoprotein receptor mutations. Curr Opin Lipidol 2021; 32:355-362. [PMID: 34653074 PMCID: PMC8631153 DOI: 10.1097/mol.0000000000000793] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE OF REVIEW Antisense oligomers (ASOs) have been available for decades: however, only recently have these molecules been applied clinically. This review aims to discuss the possible development of antisense-mediated splice correction therapies as precision medicines for familial hypercholesterolemic patients carrying mutations that compromise normal splicing of the low-density lipoprotein receptor (LDLR) gene transcript. RECENT FINDINGS Three antisense drugs are currently being assessed in ongoing clinical trials for dyslipidemias, aiming to lower the plasma concentrations of lipoproteins that lead to end-organ damage, principally coronary artery disease. Although a handful of drugs may be applicable to many patients with familial hypercholesterolemia (FH), mutation-specific personalised antisense drugs may be even more effective in selected patients. Currently, there is no therapy that effectively addresses mutations in the LDLR, the major cause of FH. Many mutations in the LDLR that disrupt normal pre-mRNA processing could be applicable to splice correction therapy to restore receptor activity. SUMMARY Precision medicine could provide long-term economic and social benefits if they can be implemented effectively and sustainably. Many mutations found in the LDLR gene could be amendable to therapeutic splice correction and we should consider developing a therapeutic ASO platform for these mutations.
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Affiliation(s)
- Craig S. McIntosh
- Perron Institute for Neurological and Translational Science, Nedlands, Western Australia, Australia
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Murdoch, Western Australia, Australia
| | - Gerald F. Watts
- School of Medicine, University of Western Australia
- Lipid Disorders Clinic, Department of Cardiology, Royal Perth Hospital, Perth, Western Australia, Australia
| | - Steve D. Wilton
- Perron Institute for Neurological and Translational Science, Nedlands, Western Australia, Australia
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Murdoch, Western Australia, Australia
| | - May T. Aung-Htut
- Perron Institute for Neurological and Translational Science, Nedlands, Western Australia, Australia
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Murdoch, Western Australia, Australia
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6
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Ham KA, Keegan NP, McIntosh CS, Aung-Htut MT, Zaw K, Greer K, Fletcher S, Wilton SD. Induction of cryptic pre-mRNA splice-switching by antisense oligonucleotides. Sci Rep 2021; 11:15137. [PMID: 34302060 PMCID: PMC8302632 DOI: 10.1038/s41598-021-94639-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 07/14/2021] [Indexed: 11/09/2022] Open
Abstract
Antisense oligomers (AOs) are increasingly being used to modulate RNA splicing in live cells, both for research and for the development of therapeutics. While the most common intended effect of these AOs is to induce skipping of whole exons, rare examples are emerging of AOs that induce skipping of only part of an exon, through activation of an internal cryptic splice site. In this report, we examined seven AO-induced cryptic splice sites in six genes. Five of these cryptic splice sites were discovered through our own experiments, and two originated from other published reports. We modelled the predicted effects of AO binding on the secondary structure of each of the RNA targets, and how these alterations would in turn affect the accessibility of the RNA to splice factors. We observed that a common predicted effect of AO binding was disruption of the exon definition signal within the exon's excluded segment.
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Affiliation(s)
- Kristin A Ham
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Perth, WA, 6150, Australia.,Perron Institute for Neurological and Translational Science, Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Perth, WA, 6009, Australia
| | - Niall P Keegan
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Perth, WA, 6150, Australia.,Perron Institute for Neurological and Translational Science, Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Perth, WA, 6009, Australia
| | - Craig S McIntosh
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Perth, WA, 6150, Australia.,Perron Institute for Neurological and Translational Science, Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Perth, WA, 6009, Australia
| | - May T Aung-Htut
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Perth, WA, 6150, Australia.,Perron Institute for Neurological and Translational Science, Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Perth, WA, 6009, Australia
| | - Khine Zaw
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Perth, WA, 6150, Australia.,Perron Institute for Neurological and Translational Science, Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Perth, WA, 6009, Australia.,Department of Biochemistry, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, 10700, Thailand
| | - Kane Greer
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Perth, WA, 6150, Australia.,Perron Institute for Neurological and Translational Science, Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Perth, WA, 6009, Australia
| | - Sue Fletcher
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Perth, WA, 6150, Australia.,Perron Institute for Neurological and Translational Science, Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Perth, WA, 6009, Australia
| | - Steve D Wilton
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Perth, WA, 6150, Australia. .,Perron Institute for Neurological and Translational Science, Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Perth, WA, 6009, Australia.
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7
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Weber JJ, Haas E, Maringer Y, Hauser S, Casadei NLP, Chishti AH, Riess O, Hübener-Schmid J. Calpain-1 ablation partially rescues disease-associated hallmarks in models of Machado-Joseph disease. Hum Mol Genet 2021; 29:892-906. [PMID: 31960910 DOI: 10.1093/hmg/ddaa010] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 01/14/2020] [Accepted: 01/16/2020] [Indexed: 12/13/2022] Open
Abstract
Proteolytic fragmentation of polyglutamine-expanded ataxin-3 is a concomitant and modifier of the molecular pathogenesis of Machado-Joseph disease (MJD), the most common autosomal dominant cerebellar ataxia. Calpains, a group of calcium-dependent cysteine proteases, are important mediators of ataxin-3 cleavage and implicated in multiple neurodegenerative conditions. Pharmacologic and genetic approaches lowering calpain activity showed beneficial effects on molecular and behavioural disease characteristics in MJD model organisms. However, specifically targeting one of the calpain isoforms by genetic means has not yet been evaluated as a potential therapeutic strategy. In our study, we tested whether calpains are overactivated in the MJD context and if reduction or ablation of calpain-1 expression ameliorates the disease-associated phenotype in MJD cells and mice. In all analysed MJD models, we detected an elevated calpain activity at baseline. Lowering or removal of calpain-1 in cells or mice counteracted calpain system overactivation and led to reduced cleavage of ataxin-3 without affecting its aggregation. Moreover, calpain-1 knockout in YAC84Q mice alleviated excessive fragmentation of important synaptic proteins. Despite worsening some motor characteristics, YAC84Q mice showed a rescue of body weight loss and extended survival upon calpain-1 knockout. Together, our findings emphasize the general potential of calpains as a therapeutic target in MJD and other neurodegenerative diseases.
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Affiliation(s)
- Jonasz J Weber
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen 72076, Germany.,Centre for Rare Diseases, University of Tübingen, Tübingen 72076, Germany.,Department of Human Genetics, Ruhr-University Bochum, Bochum 44801, Germany
| | - Eva Haas
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen 72076, Germany.,Centre for Rare Diseases, University of Tübingen, Tübingen 72076, Germany
| | - Yacine Maringer
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen 72076, Germany.,Centre for Rare Diseases, University of Tübingen, Tübingen 72076, Germany
| | - Stefan Hauser
- German Center for Neurodegenerative Diseases, Tübingen 72076, Germany
| | - Nicolas L P Casadei
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen 72076, Germany.,Centre for Rare Diseases, University of Tübingen, Tübingen 72076, Germany
| | - Athar H Chishti
- Department of Developmental, Molecular and Chemical Biology, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Olaf Riess
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen 72076, Germany.,Centre for Rare Diseases, University of Tübingen, Tübingen 72076, Germany
| | - Jeannette Hübener-Schmid
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen 72076, Germany.,Centre for Rare Diseases, University of Tübingen, Tübingen 72076, Germany
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8
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Borbolla-Jiménez FV, Del Prado-Audelo ML, Cisneros B, Caballero-Florán IH, Leyva-Gómez G, Magaña JJ. New Perspectives of Gene Therapy on Polyglutamine Spinocerebellar Ataxias: From Molecular Targets to Novel Nanovectors. Pharmaceutics 2021; 13:1018. [PMID: 34371710 PMCID: PMC8309146 DOI: 10.3390/pharmaceutics13071018] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 06/25/2021] [Accepted: 06/29/2021] [Indexed: 01/03/2023] Open
Abstract
Seven of the most frequent spinocerebellar ataxias (SCAs) are caused by a pathological expansion of a cytosine, adenine and guanine (CAG) trinucleotide repeat located in exonic regions of unrelated genes, which in turn leads to the synthesis of polyglutamine (polyQ) proteins. PolyQ proteins are prone to aggregate and form intracellular inclusions, which alter diverse cellular pathways, including transcriptional regulation, protein clearance, calcium homeostasis and apoptosis, ultimately leading to neurodegeneration. At present, treatment for SCAs is limited to symptomatic intervention, and there is no therapeutic approach to prevent or reverse disease progression. This review provides a compilation of the experimental advances obtained in cell-based and animal models toward the development of gene therapy strategies against polyQ SCAs, providing a discussion of their potential application in clinical trials. In the second part, we describe the promising potential of nanotechnology developments to treat polyQ SCA diseases. We describe, in detail, how the design of nanoparticle (NP) systems with different physicochemical and functionalization characteristics has been approached, in order to determine their ability to evade the immune system response and to enhance brain delivery of molecular tools. In the final part of this review, the imminent application of NP-based strategies in clinical trials for the treatment of polyQ SCA diseases is discussed.
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Affiliation(s)
- Fabiola V. Borbolla-Jiménez
- Laboratorio de Medicina Genómica, Departamento de Genética, Instituto Nacional de Rehabilitación-Luis Guillermo Ibarra Ibarra, Ciudad de México 14389, Mexico;
- Programa de Ciencias Biomédicas, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico
| | - María Luisa Del Prado-Audelo
- Departamento de Bioingeniería, Escuela de Ingeniería y Ciencias, Tecnológico de Monterrey Campus Ciudad de México, Ciudad de México 14380, Mexico;
| | - Bulmaro Cisneros
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV), Ciudad de México 07360, Mexico;
| | - Isaac H. Caballero-Florán
- Departamento de Farmacia, Facultad de Química, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico;
- Departamento de Farmacia, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV), Ciudad de México 07360, Mexico
| | - Gerardo Leyva-Gómez
- Departamento de Farmacia, Facultad de Química, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico;
| | - Jonathan J. Magaña
- Laboratorio de Medicina Genómica, Departamento de Genética, Instituto Nacional de Rehabilitación-Luis Guillermo Ibarra Ibarra, Ciudad de México 14389, Mexico;
- Departamento de Bioingeniería, Escuela de Ingeniería y Ciencias, Tecnológico de Monterrey Campus Ciudad de México, Ciudad de México 14380, Mexico;
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9
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Paß T, Wiesner RJ, Pla-Martín D. Selective Neuron Vulnerability in Common and Rare Diseases-Mitochondria in the Focus. Front Mol Biosci 2021; 8:676187. [PMID: 34295920 PMCID: PMC8290884 DOI: 10.3389/fmolb.2021.676187] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 06/08/2021] [Indexed: 12/12/2022] Open
Abstract
Mitochondrial dysfunction is a central feature of neurodegeneration within the central and peripheral nervous system, highlighting a strong dependence on proper mitochondrial function of neurons with especially high energy consumptions. The fitness of mitochondria critically depends on preservation of distinct processes, including the maintenance of their own genome, mitochondrial dynamics, quality control, and Ca2+ handling. These processes appear to be differently affected in common neurodegenerative diseases, such as Alzheimer’s and Parkinson’s disease, as well as in rare neurological disorders, including Huntington’s disease, Amyotrophic Lateral Sclerosis and peripheral neuropathies. Strikingly, particular neuron populations of different morphology and function perish in these diseases, suggesting that cell-type specific factors contribute to the vulnerability to distinct mitochondrial defects. Here we review the disruption of mitochondrial processes in common as well as in rare neurological disorders and its impact on selective neurodegeneration. Understanding discrepancies and commonalities regarding mitochondrial dysfunction as well as individual neuronal demands will help to design new targets and to make use of already established treatments in order to improve treatment of these diseases.
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Affiliation(s)
- Thomas Paß
- Center for Physiology and Pathophysiology, Institute of Vegetative Physiology, University of Cologne, Cologne, Germany
| | - Rudolf J Wiesner
- Center for Physiology and Pathophysiology, Institute of Vegetative Physiology, University of Cologne, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - David Pla-Martín
- Center for Physiology and Pathophysiology, Institute of Vegetative Physiology, University of Cologne, Cologne, Germany
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10
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Prudencio M, Garcia-Moreno H, Jansen-West KR, Al-Shaikh RH, Gendron TF, Heckman MG, Spiegel MR, Carlomagno Y, Daughrity LM, Song Y, Dunmore JA, Byron N, Oskarsson B, Nicholson KA, Staff NP, Gorcenco S, Puschmann A, Lemos J, Januário C, LeDoux MS, Friedman JH, Polke J, Labrum R, Shakkottai V, McLoughlin HS, Paulson HL, Konno T, Onodera O, Ikeuchi T, Tada M, Kakita A, Fryer JD, Karremo C, Gomes I, Caviness JN, Pittelkow MR, Aasly J, Pfeiffer RF, Veerappan V, Eggenberger ER, Freeman WD, Huang JF, Uitti RJ, Wierenga KJ, Marin Collazo IV, Tipton PW, van Gerpen JA, van Blitterswijk M, Bu G, Wszolek ZK, Giunti P, Petrucelli L. Toward allele-specific targeting therapy and pharmacodynamic marker for spinocerebellar ataxia type 3. Sci Transl Med 2021; 12:12/566/eabb7086. [PMID: 33087504 DOI: 10.1126/scitranslmed.abb7086] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 06/30/2020] [Indexed: 12/13/2022]
Abstract
Spinocerebellar ataxia type 3 (SCA3), caused by a CAG repeat expansion in the ataxin-3 gene (ATXN3), is characterized by neuronal polyglutamine (polyQ) ATXN3 protein aggregates. Although there is no cure for SCA3, gene-silencing approaches to reduce toxic polyQ ATXN3 showed promise in preclinical models. However, a major limitation in translating putative treatments for this rare disease to the clinic is the lack of pharmacodynamic markers for use in clinical trials. Here, we developed an immunoassay that readily detects polyQ ATXN3 proteins in human biological fluids and discriminates patients with SCA3 from healthy controls and individuals with other ataxias. We show that polyQ ATXN3 serves as a marker of target engagement in human fibroblasts, which may bode well for its use in clinical trials. Last, we identified a single-nucleotide polymorphism that strongly associates with the expanded allele, thus providing an exciting drug target to abrogate detrimental events initiated by mutant ATXN3. Gene-silencing strategies for several repeat diseases are well under way, and our results are expected to improve clinical trial preparedness for SCA3 therapies.
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Affiliation(s)
- Mercedes Prudencio
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224, USA.,Neuroscience Graduate Program, Mayo Clinic Graduate School of Biomedical Sciences, Jacksonville, FL 32224, USA
| | - Hector Garcia-Moreno
- Ataxia Centre, Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London WC1N 3BG, UK.,Ataxia Centre, National Hospital for Neurology and Neurosurgery, University College London Hospitals NHS Trust, London WC1N 3BG, UK
| | | | | | - Tania F Gendron
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224, USA.,Neuroscience Graduate Program, Mayo Clinic Graduate School of Biomedical Sciences, Jacksonville, FL 32224, USA
| | - Michael G Heckman
- Division of Biomedical Statistics and Informatics, Mayo Clinic, Jacksonville, FL 32224, USA
| | - Matthew R Spiegel
- Division of Biomedical Statistics and Informatics, Mayo Clinic, Jacksonville, FL 32224, USA
| | - Yari Carlomagno
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224, USA.,Neuroscience Graduate Program, Mayo Clinic Graduate School of Biomedical Sciences, Jacksonville, FL 32224, USA
| | | | - Yuping Song
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224, USA
| | - Judith A Dunmore
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224, USA
| | - Natalie Byron
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224, USA
| | - Björn Oskarsson
- Department of Neurology, Mayo Clinic, Jacksonville, FL 32224, USA
| | - Katharine A Nicholson
- Sean M. Healey and AMG Center for ALS, Massachusetts General Hospital (MGH), Boston, MA 02114, USA
| | - Nathan P Staff
- Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA
| | - Sorina Gorcenco
- Lund University, Skåne University Hospital, Department of Clinical Sciences Lund, Neurology, Lund 22185, Sweden
| | - Andreas Puschmann
- Lund University, Skåne University Hospital, Department of Clinical Sciences Lund, Neurology, Lund 22185, Sweden
| | - João Lemos
- Coimbra University Hospital Centre, Coimbra University, Coimbra 3000-075, Portugal
| | - Cristina Januário
- Coimbra University Hospital Centre, Coimbra University, Coimbra 3000-075, Portugal
| | - Mark S LeDoux
- University of Memphis and Veracity Neuroscience LLC, Memphis, TN 38152, USA
| | - Joseph H Friedman
- Department of Neurology, Warren Alpert Medical School of Brown University, Providence, RI 02906, USA
| | - James Polke
- Ataxia Centre, Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London WC1N 3BG, UK.,Ataxia Centre, National Hospital for Neurology and Neurosurgery, University College London Hospitals NHS Trust, London WC1N 3BG, UK
| | - Robin Labrum
- Ataxia Centre, Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London WC1N 3BG, UK.,Ataxia Centre, National Hospital for Neurology and Neurosurgery, University College London Hospitals NHS Trust, London WC1N 3BG, UK
| | - Vikram Shakkottai
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109, USA
| | | | - Henry L Paulson
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Takuya Konno
- Department of Neurology, Brain Research Institute, Niigata University, Niigata 951-8585, Japan
| | - Osamu Onodera
- Department of Neurology, Brain Research Institute, Niigata University, Niigata 951-8585, Japan
| | - Takeshi Ikeuchi
- Department of Molecular Genetics, Brain Research Institute, Niigata University, Niigata 951-8585, Japan
| | - Mari Tada
- Department of Pathology, Brain Research Institute, Niigata University, Niigata 951-8585, Japan
| | - Akiyoshi Kakita
- Department of Pathology, Brain Research Institute, Niigata University, Niigata 951-8585, Japan
| | - John D Fryer
- Neuroscience Graduate Program, Mayo Clinic Graduate School of Biomedical Sciences, Jacksonville, FL 32224, USA.,Department of Neuroscience, Mayo Clinic, Scottsdale, AZ 85259, USA
| | - Christin Karremo
- Lund University, Skåne University Hospital, Department of Clinical Sciences Lund, Neurology, Lund 22185, Sweden
| | - Inês Gomes
- Coimbra University Hospital Centre, Coimbra University, Coimbra 3000-075, Portugal
| | - John N Caviness
- Department of Neurology, Mayo Clinic, Scottsdale, AZ 85259, USA
| | - Mark R Pittelkow
- Department of Dermatology, Mayo Clinic, Scottsdale, AZ 85259, USA
| | - Jan Aasly
- Norwegian University of Science and Technology, 7006 Trondheim, Norway
| | - Ronald F Pfeiffer
- Department of Neurology, Oregon Health & Science University, Portland, OR 97239, USA
| | - Venka Veerappan
- Department of Neurology, Oregon Health & Science University, Portland, OR 97239, USA
| | | | | | | | - Ryan J Uitti
- Department of Neurology, Mayo Clinic, Jacksonville, FL 32224, USA
| | - Klaas J Wierenga
- Department of Neurology, Mayo Clinic, Jacksonville, FL 32224, USA
| | | | - Philip W Tipton
- Department of Neurology, Mayo Clinic, Jacksonville, FL 32224, USA
| | | | - Marka van Blitterswijk
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224, USA.,Neuroscience Graduate Program, Mayo Clinic Graduate School of Biomedical Sciences, Jacksonville, FL 32224, USA
| | - Guojun Bu
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224, USA.,Neuroscience Graduate Program, Mayo Clinic Graduate School of Biomedical Sciences, Jacksonville, FL 32224, USA
| | | | - Paola Giunti
- Ataxia Centre, Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London WC1N 3BG, UK. .,Ataxia Centre, National Hospital for Neurology and Neurosurgery, University College London Hospitals NHS Trust, London WC1N 3BG, UK
| | - Leonard Petrucelli
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224, USA. .,Neuroscience Graduate Program, Mayo Clinic Graduate School of Biomedical Sciences, Jacksonville, FL 32224, USA
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11
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Doxakis E. Therapeutic antisense oligonucleotides for movement disorders. Med Res Rev 2020; 41:2656-2688. [PMID: 32656818 DOI: 10.1002/med.21706] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 06/11/2020] [Accepted: 06/26/2020] [Indexed: 12/11/2022]
Abstract
Movement disorders are a group of neurological conditions characterized by abnormalities of movement and posture. They are broadly divided into akinetic and hyperkinetic syndromes. Until now, no effective symptomatic or disease-modifying therapies have been available. However, since many of these disorders are monogenic or have some well-defined genetic component, they represent strong candidates for antisense oligonucleotide (ASO) therapies. ASO therapies are based on the use of short synthetic single-stranded ASOs that bind to disease-related target RNAs via Watson-Crick base-pairing and pleiotropically modulate their function. With information arising from the RNA sequence alone, it is possible to design ASOs that not only alter the expression levels but also the splicing defects of any protein, far exceeding the intervention repertoire of traditional small molecule approaches. Following the regulatory approval of ASO therapies for spinal muscular atrophy and Duchenne muscular dystrophy in 2016, there has been tremendous momentum in testing such therapies for other neurological disorders. This review article initially focuses on the chemical modifications aimed at improving ASO effectiveness, the mechanisms by which ASOs can interfere with RNA function, delivery systems and pharmacokinetics, and the common set of toxicities associated with their application. It, then, describes the pathophysiology and the latest information on preclinical and clinical trials utilizing ASOs for the treatment of Parkinson's disease, Huntington's disease, and ataxias 1, 2, 3, and 7. It concludes with issues that require special attention to realize the full potential of ASO-based therapies.
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Affiliation(s)
- Epaminondas Doxakis
- Center of Basic Research, Biomedical Research Foundation, Academy of Athens, Athens, Greece
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12
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Silva AC, Lobo DD, Martins IM, Lopes SM, Henriques C, Duarte SP, Dodart JC, Nobre RJ, Pereira de Almeida L. Antisense oligonucleotide therapeutics in neurodegenerative diseases: the case of polyglutamine disorders. Brain 2020; 143:407-429. [PMID: 31738395 DOI: 10.1093/brain/awz328] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 08/09/2019] [Accepted: 08/22/2019] [Indexed: 12/20/2022] Open
Abstract
Polyglutamine (polyQ) disorders are a group of nine neurodegenerative diseases that share a common genetic cause, which is an expansion of CAG repeats in the coding region of the causative genes that are otherwise unrelated. The trinucleotide expansion encodes for an expanded polyQ tract in the respective proteins, resulting in toxic gain-of-function and eventually in neurodegeneration. Currently, no disease-modifying therapies are available for this group of disorders. Nevertheless, given their monogenic nature, polyQ disorders are ideal candidates for therapies that target specifically the gene transcripts. Antisense oligonucleotides (ASOs) have been under intense investigation over recent years as gene silencing tools. ASOs are small synthetic single-stranded chains of nucleic acids that target specific RNA transcripts through several mechanisms. ASOs can reduce the levels of mutant proteins by breaking down the targeted transcript, inhibit mRNA translation or alter the maturation of the pre-mRNA via splicing correction. Over the years, chemical optimization of ASO molecules has allowed significant improvement of their pharmacological properties, which has in turn made this class of therapeutics a very promising strategy to treat a variety of neurodegenerative diseases. Indeed, preclinical and clinical strategies have been developed in recent years for some polyQ disorders using ASO therapeutics. The success of ASOs in several animal models, as well as encouraging results in the clinic for Huntington's disease, points towards a promising future regarding the application of ASO-based therapies for polyQ disorders in humans, offering new opportunities to address unmet medical needs for this class of disorders. This review aims to present a brief overview of key chemical modifications, mechanisms of action and routes of administration that have been described for ASO-based therapies. Moreover, it presents a review of the most recent and relevant preclinical and clinical trials that have tested ASO therapeutics in polyQ disorders.
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Affiliation(s)
- Ana C Silva
- Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Diana D Lobo
- Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Inês M Martins
- Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,Institute for Interdisciplinary Research, University of Coimbra, Coimbra, Portugal
| | - Sara M Lopes
- Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,Institute for Interdisciplinary Research, University of Coimbra, Coimbra, Portugal
| | - Carina Henriques
- Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,ViraVector, Viral Vector for Gene Transfer Core Facility, University of Coimbra, Coimbra, Portugal
| | - Sónia P Duarte
- Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,Institute for Interdisciplinary Research, University of Coimbra, Coimbra, Portugal
| | | | - Rui Jorge Nobre
- Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,Institute for Interdisciplinary Research, University of Coimbra, Coimbra, Portugal.,ViraVector, Viral Vector for Gene Transfer Core Facility, University of Coimbra, Coimbra, Portugal
| | - Luis Pereira de Almeida
- Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,ViraVector, Viral Vector for Gene Transfer Core Facility, University of Coimbra, Coimbra, Portugal.,Faculty of Pharmacy, University of Coimbra, Coimbra, Portugal
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13
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McLoughlin HS, Moore LR, Paulson HL. Pathogenesis of SCA3 and implications for other polyglutamine diseases. Neurobiol Dis 2020; 134:104635. [PMID: 31669734 PMCID: PMC6980715 DOI: 10.1016/j.nbd.2019.104635] [Citation(s) in RCA: 88] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2019] [Revised: 09/30/2019] [Accepted: 10/03/2019] [Indexed: 12/14/2022] Open
Abstract
Tandem repeat diseases include the neurodegenerative disorders known as polyglutamine (polyQ) diseases, caused by CAG repeat expansions in the coding regions of the respective disease genes. The nine known polyQ disease include Huntington's disease (HD), dentatorubral-pallidoluysian atrophy (DRPLA), spinal bulbar muscular atrophy (SBMA), and six spinocerebellar ataxias (SCA1, SCA2, SCA3, SCA6, SCA7, and SCA17). The underlying disease mechanism in the polyQ diseases is thought principally to reflect dominant toxic properties of the disease proteins which, when harboring a polyQ expansion, differentially interact with protein partners and are prone to aggregate. Among the polyQ diseases, SCA3 is the most common SCA, and second to HD in prevalence worldwide. Here we summarize current understanding of SCA3 disease mechanisms within the broader context of the broader polyQ disease field. We emphasize properties of the disease protein, ATXN3, and new discoveries regarding three potential pathogenic mechanisms: 1) altered protein homeostasis; 2) DNA damage and dysfunctional DNA repair; and 3) nonneuronal contributions to disease. We conclude with an overview of the therapeutic implications of recent mechanistic insights.
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Affiliation(s)
| | - Lauren R Moore
- Department of Neurology, University of Michigan, Ann Arbor, MI, USA
| | - Henry L Paulson
- Department of Neurology, University of Michigan, Ann Arbor, MI, USA.
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14
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Dantuma NP, Herzog LK. Machado-Joseph Disease: A Stress Combating Deubiquitylating Enzyme Changing Sides. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1233:237-260. [PMID: 32274760 DOI: 10.1007/978-3-030-38266-7_10] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Machado-Joseph disease (MJD), also known as Spinocerebellar ataxia type 3 (SCA3), is an autosomal dominant inheritable neurodegenerative disorder. After a long pre-symptomatic period, this late-onset disease progressively disables patients and typically leads to premature death. Neuronal loss in specific regions of the cerebellum, brainstem and basal ganglia as well as the spinal cord explains the spectra of debilitating neurological symptoms, most strikingly progressive limb, and gait ataxia. The genetic cause of MJD is a polyglutamine (polyQ) repeat expansion in the gene that encodes ataxin-3. This polyQ-containing protein displays a well-defined catalytic activity as ataxin-3 is a deubiquitylating enzyme that removes and disassembles ubiquitin chains from specific substrates. While mutant ataxin-3 with an expanded polyQ repeat induces cellular stress due to its propensity to aggregate, the native functions of wild-type ataxin-3 are linked to the cellular countermeasures against the very same stress conditions inflicted by polyQ-containing and other aggregation-prone proteins. Hence, a mixture of gain-of-function and loss-of-function mechanisms are likely to contribute to the neuronal demise observed in MJD. In this review, we discuss the intimate link between ataxin-3 and cellular stress and its relevance for therapeutic intervention in MJD.
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Affiliation(s)
- Nico P Dantuma
- Department of Cell and Molecular Biology (CMB), Karolinska Institutet, Stockholm, Sweden.
| | - Laura K Herzog
- Department of Cell and Molecular Biology (CMB), Karolinska Institutet, Stockholm, Sweden
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15
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McIntosh CS, Aung-Htut MT, Fletcher S, Wilton SD. Removal of the Polyglutamine Repeat of Ataxin-3 by Redirecting pre-mRNA Processing. Int J Mol Sci 2019; 20:ijms20215434. [PMID: 31683630 PMCID: PMC6862616 DOI: 10.3390/ijms20215434] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 10/28/2019] [Accepted: 10/29/2019] [Indexed: 02/06/2023] Open
Abstract
Spinocerebellar ataxia type 3 (SCA3) is a devastating neurodegenerative disease for which there is currently no cure, nor effective treatment strategy. One of nine polyglutamine disorders known to date, SCA3 is clinically heterogeneous and the main feature is progressive ataxia, which in turn affects speech, balance and gait of the affected individual. SCA3 is caused by an expanded polyglutamine tract in the ataxin-3 protein, resulting in conformational changes that lead to toxic gain of function. The expanded glutamine tract is located at the 5′ end of the penultimate exon (exon 10) of ATXN3 gene transcript. Other studies reported removal of the expanded glutamine tract using splice switching antisense oligonucleotides. Here, we describe improved efficiency in the removal of the toxic polyglutamine tract of ataxin-3 in vitro using phosphorodiamidate morpholino oligomers, when compared to antisense oligonucleotides composed of 2′-O-methyl modified bases on a phosphorothioate backbone. Significant downregulation of both the expanded and non-expanded protein was induced by the morpholino antisense oligomer, with a greater proportion of ataxin-3 protein missing the polyglutamine tract. With growing concerns over toxicity associated with long-term administration of phosphorothioate oligonucleotides, the use of a phosphorodiamidate morpholino oligomer may be preferable for clinical application. These results suggest that morpholino oligomers may provide greater therapeutic benefit for the treatment of spinocerebellar ataxia type 3, without toxic effects.
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Affiliation(s)
- Craig S McIntosh
- Molecular Therapy Laboratory, Centre for Molecular Medicine and Innovative Therapeutics, Murdoch University, Health Research Building, Discovery Way, Murdoch WA 6150, Australia.
- Perron Institute for Neurological and Translational Science, Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Nedlands WA 6009, Australia.
| | - May Thandar Aung-Htut
- Molecular Therapy Laboratory, Centre for Molecular Medicine and Innovative Therapeutics, Murdoch University, Health Research Building, Discovery Way, Murdoch WA 6150, Australia.
- Perron Institute for Neurological and Translational Science, Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Nedlands WA 6009, Australia.
| | - Sue Fletcher
- Molecular Therapy Laboratory, Centre for Molecular Medicine and Innovative Therapeutics, Murdoch University, Health Research Building, Discovery Way, Murdoch WA 6150, Australia.
- Perron Institute for Neurological and Translational Science, Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Nedlands WA 6009, Australia.
| | - Steve D Wilton
- Molecular Therapy Laboratory, Centre for Molecular Medicine and Innovative Therapeutics, Murdoch University, Health Research Building, Discovery Way, Murdoch WA 6150, Australia.
- Perron Institute for Neurological and Translational Science, Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Nedlands WA 6009, Australia.
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16
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Nóbrega C, Codêsso JM, Mendonça L, Pereira de Almeida L. RNA Interference Therapy for Machado-Joseph Disease: Long-Term Safety Profile of Lentiviral Vectors Encoding Short Hairpin RNAs Targeting Mutant Ataxin-3. Hum Gene Ther 2019; 30:841-854. [PMID: 30760052 DOI: 10.1089/hum.2018.157] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Machado-Joseph disease (MJD) or spinocerebellar ataxia type 3 is a neurodegenerative disorder caused by an abnormal repetition of a CAG codon in the MJD1 gene. This expansion translates into a long polyglutamine tract, leading to the misfolding of the mutant protein ataxin-3, which abnormally accumulates in the nucleus, thus leading to neurodegeneration in specific brain regions. No treatment able to modify the progression of the disease is available. However, it has previously been shown that specific silencing of mutant ataxin-3 by RNA interference with viral vectors is a promising therapeutic strategy for MJD. Nevertheless, reports of cytotoxic effects of this technology led to the safety profile of the previously tested lentiviral vectors encoding short hairpin (sh)RNAs (LV-shmutatx3) targeting mutant ataxin-3 upon brain injection being investigated. For this purpose, the vectors were injected in the mouse striata, and neuronal dysfunction, degeneration, gliosis, off-target effects, and saturation of the RNA interference machinery were evaluated. It was found that: (1) LV-shmutatx3 mediated stable and long-term expression of the shRNA in neurons of the mouse striatum; (2) neuronal dysfunction evaluated by darpp-32, NeuN, and cresyl violet staining, initially more pronounced, became indistinguishable from the phosphate-buffered saline group at 8 weeks and resolved within 20 weeks; (3) astrocytic activation was present, which resolved within 8 weeks; (4) microglial activity and proinflammatory cytokines release were present, which resolved and normalized within 20 weeks; and (5) there were no off-target effects or saturation of the endogenous RNA interference processing machinery in the mouse striatum. The data show that injection of lentiviral vectors encoding a shRNA targeting mutant ataxin-3 in the mouse brain induce transient dysfunctions, which resolve within 20 weeks. Importantly, long-term expression (up to 20 weeks post injection) of this shRNA (driven by H1 promoter) led to no toxic effect in vivo. This study thus constitutes an additional step in a future translation of gene silencing as a therapy for MJD.
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Affiliation(s)
- Clévio Nóbrega
- 1Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
- 2Department of Biomedical Sciences and Medicine, University of Algarve, Faro, Portugal
- 3Centre for Biomedical Research, University of Algarve, Faro, Portugal
| | - José Miguel Codêsso
- 1Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Liliana Mendonça
- 1Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Luís Pereira de Almeida
- 1Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
- 4Faculty of Pharmacy, University of Coimbra, Coimbra, Portugal
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17
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Pitout I, Flynn LL, Wilton SD, Fletcher S. Antisense-mediated splice intervention to treat human disease: the odyssey continues. F1000Res 2019; 8. [PMID: 31164976 PMCID: PMC6534073 DOI: 10.12688/f1000research.18466.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/15/2019] [Indexed: 12/24/2022] Open
Abstract
Recent approvals of oligonucleotide analogue drugs to alter gene expression have been welcomed by patient communities but not universally supported. These compounds represent a class of drugs that are designed to target a specific gene transcript, and they include a number of chemical entities to evoke different antisense mechanisms, depending upon the disease aetiology. To date, oligonucleotide therapeutics that are in the clinic or at advanced stages of translation target rare diseases, posing challenges to clinical trial design, recruitment and evaluation and requiring new evaluation paradigms. This review discusses the currently available and emerging therapeutics that alter exon selection through an effect on pre-mRNA splicing and explores emerging concerns over safety and efficacy. Although modification of synthetic nucleic acids destined for therapeutic application is common practice to protect against nuclease degradation and to influence drug function, such modifications may also confer unexpected physicochemical and biological properties. Negatively charged oligonucleotides have a strong propensity to bind extra- and intra-cellular proteins, whereas those analogues with a neutral backbone show inefficient cellular uptake but excellent safety profiles. In addition, the potential for incorporation of chemically modified nucleic acid monomers, yielded by nuclease degradation of exogenous oligonucleotides, into biomolecules has been raised and the possibility not entirely discounted. We conclude with a commentary on the ongoing efforts to develop novel antisense compounds and enhance oligonucleotide delivery in order to further improve efficacy and accelerate implementation of antisense therapeutics for human disease.
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Affiliation(s)
| | - Loren L Flynn
- Murdoch University, Murdoch, WA, 6150, Australia.,The University of Western Australia, Nedlands, WA, 6009, Australia.,Perron Institute, Nedlands, WA, 6009, Australia
| | - Steve D Wilton
- Murdoch University, Murdoch, WA, 6150, Australia.,The University of Western Australia, Nedlands, WA, 6009, Australia.,Perron Institute, Nedlands, WA, 6009, Australia
| | - Sue Fletcher
- Murdoch University, Murdoch, WA, 6150, Australia.,The University of Western Australia, Nedlands, WA, 6009, Australia.,Perron Institute, Nedlands, WA, 6009, Australia
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18
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Ashizawa AT, Holt J, Faust K, Liu W, Tiwari A, Zhang N, Ashizawa T. Intravenously Administered Novel Liposomes, DCL64, Deliver Oligonucleotides to Cerebellar Purkinje Cells. THE CEREBELLUM 2019; 18:99-108. [PMID: 29987489 DOI: 10.1007/s12311-018-0961-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Cerebellar Purkinje cells (PCs) show conspicuous damages in many ataxic disorders. Targeted delivery of short nucleic acids, such as antisense oligonucleotides, to PCs may be a potential treatment for ataxic disorders, especially spinocerebellar ataxias (SCAs), which are mostly caused by a gain of toxic function of the mutant RNA or protein. However, oligonucleotides do not cross the blood-brain barrier (BBB), necessitating direct delivery into the central nervous system (CNS) through intra-thecal, intra-cisternal, intra-cerebral ventricular, or stereotactic parenchymal administration. We have developed a novel liposome (100 to 200 nm in diameter) formulation, DCL64, composed of dipalmitoyl-phosphatidylcholine, cholesterol, and poloxamer L64, which incorporates oligonucleotides efficiently (≥ 70%). Confocal microscopy showed that DCL64 was selectively taken up by brain microvascular endothelial cells by interacting with low-density lipoprotein receptor (LDLr) family members on cell surface, but not with other types of lipid receptors such as caveolin or scavenger receptor class B type 1. LDLr family members are implicated in brain microvascular endothelial cell endocytosis/transcytosis, and are abundantly localized on cerebellar PCs. Intravenous administration of DCL64 in normal mice showed distribution of oligonucleotides to the brain, preferentially in PCs. Mice that received DCL64 showed no adverse effect on hematological, hepatic, and renal functions in blood tests, and no histopathological abnormalities in major organs. These studies suggest that DCL64 delivers oligonucleotides to PCs across the BBB via intravenous injection with no detectable adverse effects. This property potentially makes DCL64 particularly attractive as a delivery vehicle in treatments of SCAs.
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Affiliation(s)
- Ana Tari Ashizawa
- McKnight Brain Institute, University of Florida, Gainesville, FL, USA.,Department of Neuroscience, University of Florida, Gainesville, FL, USA.,Bio-Path Holdings, Inc., Bellaire, TX, USA
| | - Jenny Holt
- McKnight Brain Institute, University of Florida, Gainesville, FL, USA.,Department of Neurology, University of Florida, Gainesville, FL, USA
| | - Kelsey Faust
- McKnight Brain Institute, University of Florida, Gainesville, FL, USA.,Department of Neuroscience, University of Florida, Gainesville, FL, USA
| | - Weier Liu
- McKnight Brain Institute, University of Florida, Gainesville, FL, USA.,Department of Neuroscience, University of Florida, Gainesville, FL, USA
| | - Anjana Tiwari
- Stanley H. Appel Department of Neurology, Houston Methodist Research Institute, 6670 Bertner Avenue, R11-117, Houston, TX, 77030, USA
| | - Nan Zhang
- Stanley H. Appel Department of Neurology, Houston Methodist Research Institute, 6670 Bertner Avenue, R11-117, Houston, TX, 77030, USA
| | - Tetsuo Ashizawa
- McKnight Brain Institute, University of Florida, Gainesville, FL, USA. .,Department of Neurology, University of Florida, Gainesville, FL, USA. .,Stanley H. Appel Department of Neurology, Houston Methodist Research Institute, 6670 Bertner Avenue, R11-117, Houston, TX, 77030, USA.
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19
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Buijsen RAM, Toonen LJA, Gardiner SL, van Roon-Mom WMC. Genetics, Mechanisms, and Therapeutic Progress in Polyglutamine Spinocerebellar Ataxias. Neurotherapeutics 2019; 16:263-286. [PMID: 30607747 PMCID: PMC6554265 DOI: 10.1007/s13311-018-00696-y] [Citation(s) in RCA: 86] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Autosomal dominant cerebellar ataxias (ADCAs) are a group of neurodegenerative disorders characterized by degeneration of the cerebellum and its connections. All ADCAs have progressive ataxia as their main clinical feature, frequently accompanied by dysarthria and oculomotor deficits. The most common spinocerebellar ataxias (SCAs) are 6 polyglutamine (polyQ) SCAs. These diseases are all caused by a CAG repeat expansion in the coding region of a gene. Currently, no curative treatment is available for any of the polyQ SCAs, but increasing knowledge on the genetics and the pathological mechanisms of these polyQ SCAs has provided promising therapeutic targets to potentially slow disease progression. Potential treatments can be divided into pharmacological and gene therapies that target the toxic downstream effects, gene therapies that target the polyQ SCA genes, and stem cell replacement therapies. Here, we will provide a review on the genetics, mechanisms, and therapeutic progress in polyglutamine spinocerebellar ataxias.
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Affiliation(s)
- Ronald A M Buijsen
- Department of Human Genetics, LUMC, P.O. Box 9600, 2300 RC, Leiden, The Netherlands.
| | - Lodewijk J A Toonen
- Department of Human Genetics, LUMC, P.O. Box 9600, 2300 RC, Leiden, The Netherlands
| | - Sarah L Gardiner
- Department of Human Genetics, LUMC, P.O. Box 9600, 2300 RC, Leiden, The Netherlands
- Department of Neurology, LUMC, P.O. Box 9600, 2300 RC, Leiden, The Netherlands
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20
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Matos CA, de Almeida LP, Nóbrega C. Machado-Joseph disease/spinocerebellar ataxia type 3: lessons from disease pathogenesis and clues into therapy. J Neurochem 2018; 148:8-28. [PMID: 29959858 DOI: 10.1111/jnc.14541] [Citation(s) in RCA: 83] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 06/05/2018] [Accepted: 06/27/2018] [Indexed: 12/25/2022]
Abstract
Machado-Joseph disease (MJD), also known as spinocerebellar ataxia type 3 (SCA3), is an incurable disorder, widely regarded as the most common form of spinocerebellar ataxia in the world. MJD/SCA3 arises from mutation of the ATXN3 gene, but this simple monogenic cause contrasts with the complexity of the pathogenic mechanisms that are currently admitted to underlie neuronal dysfunction and death. The aberrantly expanded protein product - ataxin-3 - is known to aggregate and generate toxic species that disrupt several cell systems, including autophagy, proteostasis, transcription, mitochondrial function and signalling. Over the years, research into putative therapeutic approaches has often been devoted to the development of strategies that counteract disease at different stages of cellular pathogenesis. Silencing the pathogenic protein, blocking aggregation, inhibiting toxic proteolytic processing and counteracting dysfunctions of the cellular systems affected have yielded promising ameliorating results in studies with cellular and animal models. The current review analyses the available studies dedicated to the investigation of MJD/SCA3 pathogenesis and the exploration of possible therapeutic strategies, focusing primarily on gene therapy and pharmacological approaches rooted on the molecular and cellular mechanisms of disease.
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Affiliation(s)
- Carlos A Matos
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal.,Institute for Interdisciplinary Research, University of Coimbra, Coimbra, Portugal
| | - Luís Pereira de Almeida
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal.,Faculty of Pharmacy, University of Coimbra, Coimbra, Portugal
| | - Clévio Nóbrega
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal.,Department of Biomedical Sciences and Medicine, University of Algarve, Coimbra, Portugal.,Centre for Biomedical Research (CBMR), University of Algarve, Coimbra, Portugal.,Algarve Biomedical Center (ABC), University of Algarve, Faro, Portugal
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21
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Abstract
Spinocerebellar ataxia (SCA) is a heterogeneous group of neurodegenerative ataxic disorders with autosomal dominant inheritance. We aim to provide an update on the recent clinical and scientific progresses in SCA where numerous novel genes have been identified with next-generation sequencing techniques. The main disease mechanisms of these SCAs include toxic RNA gain-of-function, mitochondrial dysfunction, channelopathies, autophagy and transcription dysregulation. Recent studies have also demonstrated the importance of DNA repair pathways in modifying SCA with CAG expansions. In addition, we summarise the latest technological advances in detecting known and novel repeat expansion in SCA. Finally, we discuss the roles of antisense oligonucleotides and RNA-based therapy as potential treatments.
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Abstract
Polyglutamine diseases are hereditary degenerative disorders of the nervous system that have remained, to this date, untreatable. Promisingly, investigation into their molecular etiology and the development of increasingly perfected tools have contributed to the design of novel strategies with therapeutic potential. Encouraging studies have explored gene therapy as a means to counteract cell demise and loss in this context. The current chapter addresses the two main focuses of research in the area: the characteristics of the systems used to deliver nucleic acids to cells and the molecular and cellular actions of the therapeutic agents. Vectors used in gene therapy have to satisfyingly reach the tissues and cell types of interest, while eliciting the lowest toxicity possible. Both viral and non-viral systems have been developed for the delivery of nucleic acids to the central nervous system, each with its respective advantages and shortcomings. Since each polyglutamine disease is caused by mutation of a single gene, many gene therapy strategies have tried to halt degeneration by silencing the corresponding protein products, usually recurring to RNA interference. The potential of small interfering RNAs, short hairpin RNAs and microRNAs has been investigated. Overexpression of protective genes has also been evaluated as a means of decreasing mutant protein toxicity and operate beneficial alterations. Recent gene editing tools promise yet other ways of interfering with the disease-causing genes, at the most upstream points possible. Results obtained in both cell and animal models encourage further delving into this type of therapeutic strategies and support the future use of gene therapy in the treatment of polyglutamine diseases.
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Toonen LJA, Overzier M, Evers MM, Leon LG, van der Zeeuw SAJ, Mei H, Kielbasa SM, Goeman JJ, Hettne KM, Magnusson OT, Poirel M, Seyer A, 't Hoen PAC, van Roon-Mom WMC. Transcriptional profiling and biomarker identification reveal tissue specific effects of expanded ataxin-3 in a spinocerebellar ataxia type 3 mouse model. Mol Neurodegener 2018; 13:31. [PMID: 29929540 PMCID: PMC6013885 DOI: 10.1186/s13024-018-0261-9] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 05/23/2018] [Indexed: 12/12/2022] Open
Abstract
Background Spinocerebellar ataxia type 3 (SCA3) is a progressive neurodegenerative disorder caused by expansion of the polyglutamine repeat in the ataxin-3 protein. Expression of mutant ataxin-3 is known to result in transcriptional dysregulation, which can contribute to the cellular toxicity and neurodegeneration. Since the exact causative mechanisms underlying this process have not been fully elucidated, gene expression analyses in brains of transgenic SCA3 mouse models may provide useful insights. Methods Here we characterised the MJD84.2 SCA3 mouse model expressing the mutant human ataxin-3 gene using a multi-omics approach on brain and blood. Gene expression changes in brainstem, cerebellum, striatum and cortex were used to study pathological changes in brain, while blood gene expression and metabolites/lipids levels were examined as potential biomarkers for disease. Results Despite normal motor performance at 17.5 months of age, transcriptional changes in brain tissue of the SCA3 mice were observed. Most transcriptional changes occurred in brainstem and striatum, whilst cerebellum and cortex were only modestly affected. The most significantly altered genes in SCA3 mouse brain were Tmc3, Zfp488, Car2, and Chdh. Based on the transcriptional changes, α-adrenergic and CREB pathways were most consistently altered for combined analysis of the four brain regions. When examining individual brain regions, axon guidance and synaptic transmission pathways were most strongly altered in striatum, whilst brainstem presented with strongest alterations in the pi-3 k cascade and cholesterol biosynthesis pathways. Similar to other neurodegenerative diseases, reduced levels of tryptophan and increased levels of ceramides, di- and triglycerides were observed in SCA3 mouse blood. Conclusions The observed transcriptional changes in SCA3 mouse brain reveal parallels with previous reported neuropathology in patients, but also shows brain region specific effects as well as involvement of adrenergic signalling and CREB pathway changes in SCA3. Importantly, the transcriptional changes occur prior to onset of motor- and coordination deficits. Electronic supplementary material The online version of this article (10.1186/s13024-018-0261-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Lodewijk J A Toonen
- Department of Human Genetics, Leiden University Medical Center, 2300 RC, Leiden, The Netherlands
| | - Maurice Overzier
- Department of Human Genetics, Leiden University Medical Center, 2300 RC, Leiden, The Netherlands
| | - Melvin M Evers
- Department of Research & Development, uniQure, Amsterdam, The Netherlands
| | - Leticia G Leon
- Cancer Pharmacology Lab, University of Pisa, Ospedale di Cisanello, Edificio 6 via Paradisa, 2, 56124, Pisa, Italy
| | - Sander A J van der Zeeuw
- Sequencing Analysis Support Core, Leiden University Medical Center, 2300 RC, Leiden, The Netherlands
| | - Hailiang Mei
- Sequencing Analysis Support Core, Leiden University Medical Center, 2300 RC, Leiden, The Netherlands
| | - Szymon M Kielbasa
- Department of Biomedical Data Sciences, Leiden University Medical Center, 2300 RC, Leiden, The Netherlands
| | - Jelle J Goeman
- Department of Biomedical Data Sciences, Leiden University Medical Center, 2300 RC, Leiden, The Netherlands
| | - Kristina M Hettne
- Department of Human Genetics, Leiden University Medical Center, 2300 RC, Leiden, The Netherlands
| | | | | | | | - Peter A C 't Hoen
- Department of Human Genetics, Leiden University Medical Center, 2300 RC, Leiden, The Netherlands.,Centre for Molecular and Biomolecular Informatics, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6500 HB, Nijmegen, The Netherlands
| | - Willeke M C van Roon-Mom
- Department of Human Genetics, Leiden University Medical Center, 2300 RC, Leiden, The Netherlands.
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Toonen LJA, Casaca-Carreira J, Pellisé-Tintoré M, Mei H, Temel Y, Jahanshahi A, van Roon-Mom WMC. Intracerebroventricular Administration of a 2'-O-Methyl Phosphorothioate Antisense Oligonucleotide Results in Activation of the Innate Immune System in Mouse Brain. Nucleic Acid Ther 2018; 28:63-73. [PMID: 29565739 PMCID: PMC5899290 DOI: 10.1089/nat.2017.0705] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Antisense oligonucleotides (AONs) are versatile molecules that can be used to modulate gene expression by binding to RNA. The therapeutic potential of AONs appears particularly high in the central nervous system, due to excellent distribution and uptake in brain cells, as well as good tolerability in clinical trials thus far. Nonetheless, immune stimulation in response to AON treatment in the brain remains a concern. For this reason we performed RNA sequencing analysis of brain tissue from mice treated intracerebroventricularly with phosphorothioate, 2′-O-methyl modified AONs. A significant upregulation of immune system associated genes was observed in brains of AON treated mice, with the striatum showing largest transcriptional changes. Strongest upregulation was seen for the antiviral enzyme 2′-5′-oligoadenylate synthase-like protein 2 (Oasl2) and Bone marrow stromal antigen 2 (Bst2). Histological analysis confirmed activation of microglia and astrocytes in striatum. The upregulation of immune system associated genes was detectable for at least 2 months after the last AON administration, consistent with a continuous immune response to the AON.
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Affiliation(s)
- Lodewijk J A Toonen
- 1 Department of Human Genetics, Leiden University Medical Center , Leiden, the Netherlands
| | - João Casaca-Carreira
- 2 Department of Neurosurgery, Maastricht University Medical Center , Maastricht, the Netherlands .,3 European Graduate School of Neuroscience (EURON) , Maastricht, the Netherlands .,4 Department of Physiotherapy, Portuguese Red Cross Health School , Lisbon, Portugal .,5 Department of Physiotherapy, School of Health Care , Setubal Polytechnic Institute, Setubal, Portugal
| | - Maria Pellisé-Tintoré
- 2 Department of Neurosurgery, Maastricht University Medical Center , Maastricht, the Netherlands .,6 Department of Medical Science, Faculty of Medicine, University of Girona (UdG) , Girona, Spain
| | - Hailiang Mei
- 7 Sequencing Analysis Support Core, Leiden University Medical Center , Leiden, the Netherlands
| | - Yasin Temel
- 2 Department of Neurosurgery, Maastricht University Medical Center , Maastricht, the Netherlands .,3 European Graduate School of Neuroscience (EURON) , Maastricht, the Netherlands
| | - Ali Jahanshahi
- 2 Department of Neurosurgery, Maastricht University Medical Center , Maastricht, the Netherlands .,3 European Graduate School of Neuroscience (EURON) , Maastricht, the Netherlands
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Zeitlberger A, Ging H, Nethisinghe S, Giunti P. Advances in the understanding of hereditary ataxia – implications for future patients. Expert Opin Orphan Drugs 2018. [DOI: 10.1080/21678707.2018.1444477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Affiliation(s)
- Anna Zeitlberger
- Department of Molecular Neuroscience, UCL Institute of Neurology, London, UK
| | - Heather Ging
- Department of Molecular Neuroscience, UCL Institute of Neurology, London, UK
| | - Suran Nethisinghe
- Department of Molecular Neuroscience, UCL Institute of Neurology, London, UK
| | - Paola Giunti
- Department of Molecular Neuroscience, UCL, Institute of Neurology, National Hospital for Neurology and Neurosurgery, London, UK
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RD-Connect, NeurOmics and EURenOmics: collaborative European initiative for rare diseases. Eur J Hum Genet 2018; 26:778-785. [PMID: 29487416 PMCID: PMC5974013 DOI: 10.1038/s41431-018-0115-5] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 12/21/2017] [Accepted: 01/24/2018] [Indexed: 12/23/2022] Open
Abstract
Although individually uncommon, rare diseases (RDs) collectively affect 6–8% of the population. The unmet need of the rare disease community was recognized by the European Commission which in 2012 funded three flagship projects, RD-Connect, NeurOmics, and EURenOmics, to help move the field forward with the ambition of advancing -omics research and data sharing at their core in line with the goals of IRDiRC (International Rare Disease Research Consortium). NeurOmics and EURenOmics generate -omics data and improve diagnosis and therapy in rare renal and neurological diseases, with RD-Connect developing an infrastructure to facilitate the sharing, systematic integration and analysis of these data. Here, we summarize the achievements of these three projects, their impact on the RD community and their vision for the future. We also report from the Joint Outreach Day organized by the three projects on the 3rd of May 2017 in Berlin. The workshop stimulated an open, multi-stakeholder discussion on the challenges of the rare diseases, and highlighted the cross-project cooperation and the common goal: the use of innovative genomic technologies in rare disease research.
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Wang Z. Experimental and Clinical Strategies for Treating Spinocerebellar Ataxia Type 3. Neuroscience 2017; 371:138-154. [PMID: 29229556 DOI: 10.1016/j.neuroscience.2017.11.051] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Revised: 11/28/2017] [Accepted: 11/30/2017] [Indexed: 01/02/2023]
Abstract
Spinocerebellar ataxia type 3 (SCA3), or Machado-Joseph disease (MJD), is an autosomal dominant neurodegenerative disorder caused by the expansion of a polyglutamine (polyQ) tract in the ataxin-3 protein. To date, there is no effective therapy available to prevent progression of this disease. However, clinical strategies for alleviating various symptoms are imperative to promote a better quality of life for SCA3/MJD patients. Furthermore, experimental therapeutic strategies, including gene silencing or mutant protein clearance, mutant polyQ protein modification, stabilizing the native protein conformation, rescue of cellular dysfunction and neuromodulation to slow the progression of SCA3/MJD, have been developed. In this study, based on the current knowledge, I detail the clinical and experimental therapeutic strategies for treating SCA3/MJD, paying particular attention to drug discovery.
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Affiliation(s)
- Zijian Wang
- Genetic Engineering Laboratory, College of Biological and Environmental Engineering, Xi'an University, Xi'an, Shaanxi 710065, China.
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28
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Toonen LJA, Rigo F, van Attikum H, van Roon-Mom WMC. Antisense Oligonucleotide-Mediated Removal of the Polyglutamine Repeat in Spinocerebellar Ataxia Type 3 Mice. MOLECULAR THERAPY-NUCLEIC ACIDS 2017; 8:232-242. [PMID: 28918024 PMCID: PMC5504086 DOI: 10.1016/j.omtn.2017.06.019] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Revised: 06/21/2017] [Accepted: 06/24/2017] [Indexed: 11/05/2022]
Abstract
Spinocerebellar ataxia type 3 (SCA3) is a currently incurable neurodegenerative disorder caused by a CAG triplet expansion in exon 10 of the ATXN3 gene. The resultant expanded polyglutamine stretch in the mutant ataxin-3 protein causes a gain of toxic function, which eventually leads to neurodegeneration. One important function of ataxin-3 is its involvement in the proteasomal protein degradation pathway, and long-term downregulation of the protein may therefore not be desirable. In the current study, we made use of antisense oligonucleotides to mask predicted exonic splicing signals, resulting in exon 10 skipping from ATXN3 pre-mRNA. This led to formation of a truncated ataxin-3 protein lacking the toxic polyglutamine expansion, but retaining its ubiquitin binding and cleavage function. Repeated intracerebroventricular injections of the antisense oligonucleotides in a SCA3 mouse model led to exon skipping and formation of the modified ataxin-3 protein throughout the mouse brain. Exon skipping was long lasting, with the modified protein being detectable for at least 2.5 months after antisense oligonucleotide injection. A reduction in insoluble ataxin-3 and nuclear accumulation was observed following antisense oligonucleotide treatment, indicating a beneficial effect on pathogenicity. Together, these data suggest that exon 10 skipping is a promising therapeutic approach for SCA3.
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Affiliation(s)
- Lodewijk J A Toonen
- Department of Human Genetics, Leiden University Medical Center, Albinusdreef 2, 2333ZA Leiden, the Netherlands
| | - Frank Rigo
- Ionis Pharmaceuticals, Carlsbad, CA 92008, USA
| | - Haico van Attikum
- Department of Human Genetics, Leiden University Medical Center, Albinusdreef 2, 2333ZA Leiden, the Netherlands
| | - Willeke M C van Roon-Mom
- Department of Human Genetics, Leiden University Medical Center, Albinusdreef 2, 2333ZA Leiden, the Netherlands.
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29
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Abstract
The most common dominantly inherited ataxia, spinocerebellar ataxia type 3 (SCA3), is an incurable neurodegenerative disorder caused by a CAG repeat expansion in the ATXN3 gene that encodes an abnormally long polyglutamine tract in the disease protein, ATXN3. Mice lacking ATXN3 are phenotypically normal; hence, disease gene suppression offers a compelling approach to slow the neurodegenerative cascade in SCA3. Here we tested antisense oligonucleotides (ASOs) that target human ATXN3 in two complementary mouse models of SCA3: yeast artificial chromosome (YAC) MJD-Q84.2 (Q84) mice expressing the full-length human ATXN3 gene and cytomegalovirus (CMV) MJD-Q135 (Q135) mice expressing a human ATXN3 cDNA. Intracerebroventricular injection of ASOs resulted in widespread delivery to the most vulnerable brain regions in SCA3. In treated Q84 mice, three of five tested ASOs reduced disease protein levels by >50% in the diencephalon, cerebellum, and cervical spinal cord. Two ASOs also significantly reduced mutant ATXN3 in the mouse forebrain and resulted in no signs of astrogliosis or microgliosis. In Q135 mice expressing a single ATXN3 isoform via a cDNA transgene, ASOs did not result in similar robust ATXN3 silencing. Our results indicate that ASOs targeting full-length human ATXN3 would likely be well tolerated and could lead to a preventative therapy for SCA3.
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